build: Handle co-authors (ref #3744) (#8708)

The authorship script didn't pick up people who were only ever
"co-authors" of a commit, such as when they wrote stuff which was later
included in a PR by someone else, or added code during code review.

This modified the script to look closer in the commit bodies for
"Co-authored-by:"-lines and adds those found to the set of authors.

AUTHORS

@@ -23,6 +23,7 @@ Alessandro G. (alessandro.g89) <alessandro.g89@gmail.com>
 Alex Lindeman <139387+aelindeman@users.noreply.github.com>
 Alex Xu <alex.hello71@gmail.com>
 Alexander Graf (alex2108) <register-github@alex-graf.de>
+Alexandre Alves <alexandrealvesdb.contact@gmail.com>
 Alexandre Viau (aviau) <alexandre@alexandreviau.net> <aviau@debian.org>
 Aman Gupta <aman@tmm1.net>
 Anderson Mesquita (andersonvom) <andersonvom@gmail.com>
@@ -101,7 +102,7 @@ Elias Jarlebring (jarlebring) <jarlebring@gmail.com>
 Elliot Huffman <thelich2@gmail.com>
 Emil Hessman (ceh) <emil@hessman.se>
 Eng Zer Jun <engzerjun@gmail.com>
-entity0xfe <109791748+entity0xfe@users.noreply.github.com>
+entity0xfe <109791748+entity0xfe@users.noreply.github.com> <entity0xfe@my.domain>
 Eric Lesiuta <elesiuta@gmail.com>
 Eric P <eric@kastelo.net>
 Erik Meitner (WSGCSysadmin) <e.meitner@willystreet.coop>
@@ -146,6 +147,7 @@ Jaroslav Malec (dzarda) <dzardacz@gmail.com>
 jaseg <githubaccount@jaseg.net>
 Jauder Ho <jauderho@users.noreply.github.com>
 Jaya Chithra (jayachithra) <s.k.jayachithra@gmail.com>
+Jaya Kumar <jaya.kumar@ict.nl>
 Jeffery To <jeffery.to@gmail.com>
 jelle van der Waa <jelle@vdwaa.nl>
 Jens Diemer (jedie) <github.com@jensdiemer.de> <git@jensdiemer.de>
@@ -267,7 +269,7 @@ Sacheendra Talluri (sacheendra) <sacheendra.t@gmail.com>
 Scott Klupfel (kluppy) <kluppy@going2blue.com>
 sec65 <106604020+sec65@users.noreply.github.com>
 Sergey Mishin (ralder) <ralder@yandex.ru>
-Shaarad Dalvi <60266155+shaaraddalvi@users.noreply.github.com>
+Shaarad Dalvi <60266155+shaaraddalvi@users.noreply.github.com> <shdalv@microsoft.com>
 Simon Frei (imsodin) <freisim93@gmail.com>
 Simon Mwepu <simonmwepu@gmail.com>
 Sly_tom_cat <slytomcat@mail.ru>